Organic light emitting element, display device, image information processing device, lighting device, image forming device, exposure device, and organic photoelectric conversion element

ABSTRACT

The present disclosure provides an organic light emitting element which has a pair of electrodes and an organic compound layer disposed therebetween and in which the organic compound layer contains an organic compound represented by the following general formula [1], 
     
       
         
         
             
             
         
       
     
     wherein in the formula [1], Ar 1  and Ar 2  each independently represent an aromatic hydrocarbon group or a heteroaromatic ring group, R 1  to R 4  are each independently selected from a hydrogen atom or a substituent, R 1  and R 2  and R 3  and R 4  each may form a benzene ring, wherein the benzene ring may have at least one substituent.

BACKGROUND

Field of the Disclosure

The present disclosure relates to an organic light emitting element, adisplay device, an image information processing device, a lightingdevice, an image forming device, an exposure device, and an organicphotoelectric conversion element.

Description of the Related Art

An organic light emitting element is an electronic element having ananode, a cathode, and an organic compound layer disposed between the twoelectrodes. In the organic light emitting element, since positive holes(holes) and electrons injected from the respective electrodes arerecombined in the organic compound layer, excitons are generated, andlight is emitted when the excitons are returned to the ground state.Recent development of organic light emitting elements has beenremarkably carried out, and a thin and lightweight light emitting devicehaving a low drive voltage, various light emission wavelengths, and ahigh responsivity can be realized.

However, the light emission efficiency and the serviceable life of theorganic light emitting element can be still further improved, and inparticular, a decrease in drive voltage of the light emitting elementhas been desired.

In the organic light emitting element, in order to decrease the drivevoltage, the improvement in electron injection property is preferable.As a compound having a high electron injection property, heretofore, acompound, such as LiF, including an alkali metal or an alkaline earthmetal has been used.

In “Acidities of C2 Hydrogen Atoms in Thiazolium Cations andReactivities of Their Conjugate Bases”, Journal of American ChemicalSociety 113, 985 to 990, (1991) (hereinafter, referred to as “Non-PatentLiterature 1”) by F. G. Bordwell, a synthesis method of compoundsrepresented by 1-A and 1-B has been disclosed. However, all thosecompounds are unstable, that is, for example, 1-A is easily oxidized inthe air, and the structure of 1-B is easily transformed at roomtemperature. Those compounds have not been described as a compound to beused for an organic electric-field element.

In “Investigation the Reaction of Benzazolium Salt with Base” Chemical &Pharmaceutical Bulletin 17(7), 1,462 to 1,466, (1969) (hereinafter,referred to as “Non-Patent Literature 2”) by Akira Takamizawa, althougha synthesis method of a compound as represented by 1-C has beendescribed, the material is unstable and is easily oxidized as is thecompound represented by 1-A. This compound has not been described as amaterial to be used for an organic electric-field element.

In “Diazadithiafulvalenes as electron donor reagents”, Journal ofChemical Society, Perkin Transactions 1: Organic and Bio-OrganicChemistry 24, 3,637 to 3,643, (1999) (hereinafter, referred to as“Non-Patent Literature 3”) by Toshio Koizumi, although a synthesismethod of a compound as represented by 1-D has been described, thiscompound has not been described as a material to be used for an organicelectric-field element.

In “A Stable Thiazol-2-ylidene and Its Dimer”, Liebigs Annalen/Recueil2, 365 to 374, (1977) (hereinafter, referred to as “Non-PatentLiterature 4”) by Anthony J. Arduego, although a synthesis method of acompound as represented by 1-E has been described, this compound has notbeen described as a material to be used for an organic electric-fieldelement.

Although the organic compounds disclosed in Non-Patent Literatures 1 and2 have a high electron injection property, the reactivity thereof withmoisture is high, and hence, those compounds have a low stability in theair. Although being stable in the air, the organic compounds disclosedin Non-Patent Literatures 3 and 4 have not been described as a materialto be used for an organic electric-field element.

SUMMARY

The present disclosure provides an organic light emitting elementcontaining an organic compound which has a high stability againstoxidation in the air and which is not likely to be structure-transformedin the air.

Accordingly, the present disclosure provides an organic light emittingelement which has a pair of electrodes and an organic compound layerdisposed therebetween and in which the organic compound layer containsan organic compound represented by the following general formula [1].

In the formula [1], Ar₁ and Ar₂ each represent an aromatic hydrocarbongroup having 6 to 24 carbon atoms with or without at least onesubstituent or a heteroaromatic ring group having 3 to 23 carbon atoms.

R₁ to R₄ are each independently selected from the group consisting of ahydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to8 carbon atoms, a phenyl group with or without at least one substituent,and a pyridyl group with or without at least one substituent. R₁ and R₂may be bonded to each other to form a benzene ring, and R₃ and R₄ mayalso be bonded to each other to form a benzene ring. The benzene ringdescribed above may have as a substituent, at least one selected fromthe group consisting of a halogen atom, a cyano group, an alkyl grouphaving 1 to 8 carbon atoms, a phenyl group with or without at least onesubstituent, and a pyridyl group with or without at least onesubstituent.

X₁ and X₂ represent a sulfur atom or an oxygen atom, and X₁ and X₂represent the same atom.

Further features of the present disclosure will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are views each showing the electron density based on themolecular orbital calculation of one example of a fulvalene compoundaccording to the present disclosure.

FIG. 2 is a view illustrating the symmetry of an organic compound usingthe fulvalene compound according to the present disclosure.

FIG. 3 is a schematic cross-sectional view showing an organic lightemitting element according to the present disclosure and a switchingelement connected thereto.

FIG. 4 is a schematic view showing one example of an image formingdevice according to the present disclosure.

FIG. 5 is a schematic view showing one example of an exposure deviceaccording to the present disclosure.

FIG. 6 is a schematic view showing one example of a lighting deviceaccording to the present disclosure.

FIG. 7 is a schematic view showing one example of an organicphotoelectric conversion element according to the present disclosure.

DESCRIPTION OF THE EMBODIMENTS

The present disclosure relates to an organic light emitting elementhaving a pair of electrodes and an organic compound layer disposedtherebetween. The organic compound layer contains an organic compoundrepresented by the general formula [1]. Since an aromatic hydrocarbongroup or a heteroaromatic ring group is provided as Ar₁ and Ar₂, theorganic compound represented by the general formula [1] has a lowreactivity with oxygen and moisture in the air and can be stablypresent. In addition, by the use of the compound described above, anorganic light emitting element having a high stability can be provided.

In this embodiment, the organic compound represented by the generalformula [1] is called a fulvalene compound according to the presentdisclosure in some cases.

The organic compound according to the present disclosure is representedby the following general formula [1] or [2].

In the formula [1], Ar₁ and Ar₂ each represent an aromatic hydrocarbongroup having 6 to 24 carbon atoms or a heteroaromatic ring group having3 to 23 carbon atoms. Ar₁ and Ar₂ each may have as a substituent, atleast one selected from the group consisting of a halogen atom, a cyanogroup, an alkyl group having 1 to 4 carbon atoms, a phenyl group, atolyl group, a xylyl group, a mesityl group, and a cumenyl group.

R₁ to R₄ are each independently selected from the group consisting of ahydrogen atom, a halogen atom, a cyano group, an alkyl group having 1 to8 carbon atoms, a phenyl group with or without at least one substituent,and a pyridyl group with or without at least one substituent.

X₁ and X₂ represent a sulfur atom or an oxygen atom, and X₁ and X₂represent the same atom. That is, when X₁ and X₂ each represent a sulfuratom, a dithiadiazafulvalene compound is formed, and when X₁ and X₂ eachrepresent an oxygen atom, a dioxadiazafulvalene compound is formed.

R₁ and R₂ may be bonded to each other to form a benzene ring, and R₃ andR₄ may also be bonded to each other to form a benzene ring. The benzenering thus formed may have at least one substituent. The substituent thatthe benzene ring may have is the same as the substituent that R₁ to R₄may have

When R₁ and R₂ are bonded to each other to form a benzene ring, and R₃and R₄ are bonded to each other to form a benzene ring, for example, anorganic compound represented by the following general formula [2] isformed.

In the formula [2], R₅ to R₁₂ are each independently selected from ahydrogen atom or a substituent. The substituent is the same as thesubstituent that R₁ to R₄ may select.

In addition, R₁ and R₂ or R₃ and R₄ in the general formula [1] may bebonded to each other to form a benzene ring. In the case describedabove, the compound thus formed is called benzodithiadiazafulvalene orbenzodioxadiazafulvalene. From a synthesis easiness point of view, whenthe ring is formed, R₁ and R₂ and R₃ and R₄ both preferably form therings.

As the aromatic hydrocarbon group having 6 to 24 carbon atoms, forexample, a phenyl group, a naphthyl group, a phenanthryl group, afluorenyl group, a fluoranthenyl group, a triphenylenyl group, ananthracenyl group, or a pyrenyl group may be mentioned.

As the heteroaromatic ring group having 3 to 23 carbon atoms, forexample, a pyridyl group, a pyrazinyl group, a pyrimidinyl group, aquinolyl group, an isoquinolyl group, a naphthyridinyl group, aquinoxalyl group, an indolyl group, a phenanthrolinyl group, adibenzothienyl group, or a dibenzofuranyl group may be mentioned.

Among the aromatic hydrocarbon groups having 6 to 24 carbon atoms, inview of the sublimation property, a phenyl group and a naphthyl group,each of which has a relatively small molecular weight, are preferable.

Among the heteroaromatic ring groups having 3 to 23 carbon atoms, inview of the sublimation property and electronic influences, a pyridylgroup, a pyrazinyl group, and a pyrimidinyl group, each of which has arelatively small molecular weight and also has an electron withdrawingproperty, are preferable.

The above Ar₁ to Ar₄ each may have a substituent. The substituent is anyone selected from the group consisting of a cyano group, an alkyl grouphaving 1 to 4 carbon atoms, an aromatic hydrocarbon group, such as aphenyl group, a tolyl group, a xylyl group, a mesityl group, or acumenyl group, and a halogen atom, such as a fluorine atom, a chlorineatom, a bromine atom, or an iodine atom.

When the halogen atom is the substituent, a fluorine atom is preferable.

As the alkyl group having 1 to 4 carbon atoms, for example, a methylgroup, an ethyl group, an n-propyl group, an iso-propyl group, ann-butyl group, an iso-butyl group, a sec-butyl group, or a tert-butylgroup may be mentioned, and a methyl group or a tert-butyl group ispreferable.

As the halogen atom represented by one of R₁ to R₄, for example, afluorine atom, a chlorine atom, a bromine atom, or an iodine atom may bementioned, and a fluorine atom is preferable.

As the alkyl group having 1 to 8 carbon atoms represented by one of R₁to R₄, for example, a methyl group, an ethyl group, an n-propyl group,an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butylgroup, a tert-butyl group, an n-pentyl group, an n-hexyl group, acyclohexyl group, or an n-octyl group may be mentioned, and a methylgroup or a tert-butyl group is preferable.

The phenyl group and the pyridyl group each represented by one of R₁ toR₄ each may have a substituent. This substituent is any one of a cyanogroup, a fluorine atom, a methyl group, and a tert-butyl group.

(Properties of Organic Compound According to Present Disclosure)

The organic compound according to the present disclosure has a baseskeleton selected from the group consisting of dithiadiazafulvalene,dioxadiazafulvalene, dibenzodithiadiazafulvalene,dibenzodioxadiazafulvalene, benzodithiadiazafulvalene, andbenzodioxadiazafulvalene. Since having an aromatic hydrocarbon group ora heteroaromatic ring group bonded to the nitrogen atom of the baseskeleton, the organic compound according to the present disclosure has ahigh stability in the air. Although the base skeleton is liable to beoxidized and has a low stability, since the nitrogen atom functioning asa reaction active portion is covered with one of the above groups, thestability is improved.

In addition, those base skeletons are each a skeleton having a highelectron injection property.

Since the organic compound according to the present disclosure has thetwo characteristics described above, the reactivity thereof with oxygenand moisture in the air is low, and hence, the atmospheric stability andthe electron injection property can be simultaneously obtained.

As a compound having a high electron injection property, although anorganic compound containing a metal may be mentioned, as a compound usedfor an organic electric-field element, an organic compound containing nometal is preferable. The advantage obtained by the use of the organiccompound for an organic electric-field element is a low solubility towater. A compound, such as a known lithium fluoride or lithiumquinolinol, containing an alkali metal has a high solubility to water.When the compound described above is used for an organic electric-fieldelement, although an injection property from the electrode to the abovecompound can be obtained, this compound is easily ionized by moisturefrom the outside, and the degradation in stability of the element may bepartially caused thereby.

Accordingly, by the use of an organic compound containing no metal, ahighly stable element may be formed.

An electron injection material preferably has a shallow HOMO level andis closed to the energy level of the electrode. In this case, the“shallow HOMO level” indicates that the absolute value thereof is small,that is, the energy level thereof is closer to the vacuum level. Inaddition, the “shallow HOMO level” means approximately the same as a lowfirst oxidation potential obtained by cyclic voltammetry (CV)measurement.

In a material having a shallow HOMO level as described above, the energybarrier of electrons injected from a cathode to an electron conductionlevel can be reduced. In order to function as the electron injectionmaterial, the first oxidation potential is preferably low to a certainextent, that is, in particular, the first oxidation potential ispreferably 0 V or less (vs. Fc/Fc⁺) and more preferably −0.8 V or less(vs. Fc/Fc⁺). In addition, “vs. Fc/Fc⁺” indicates that the potential isbased on the oxidation-reduction potential of ferrocene.

In the organic light emitting element, when the HOMO level of thecompound of the electron injection layer is shallower, in other words,when the first oxidation potential of the compound is lower, theelectron injection property from the cathode to the electron injectionlayer is higher.

On the other hand, when the first oxidation potential of the organiccompound is higher than the reduction potential of oxygen, the organiccompound is stable against oxygen. That is, the first oxidationpotential is preferably higher than the reduction potential of oxygen.Incidentally, the reduction potential (O₂/O₂ ⁻) of oxygen is −1.22 V(vs. Fc/Fc⁺) in a dimethylformamide (DMF) solvent. This has beendisclosed in “Electoreduction of oxygen in aprotic media”, Journal ofElectroanalytical Chemistry 192, 69 to 74, (1995) by D. Vasudevan.

Hence, the first oxidation potential of the organic compound ispreferably −1.20 to 0.00 V (vs. Fc/Fc⁺) and more preferably −1.20 to−0.80 V (vs. Fc/Fc⁺) in a DMF solvent. When the first oxidationpotential is in the range described above, the stability against oxygenand excellent electron injection performance can be simultaneouslyobtained.

The oxidation potential can be measured by CV. In particular, theoxidation potential can be obtained from the oxidation current peak ofCV.

The CV measurement was performed on example compounds A5 and AA9, eachof which is one example of the organic compound according to the presentdisclosure. The CV measurement was performed in an N,N-dimethylformamidesolution of 0.1 M tetrabutylammonium perchlorate. The measurement wasperformed under the conditions in which Ag/Ag⁺ was used as a referenceelectrode, Pt was used as a counter electrode, glassy carbon was used asa working electrode, an oxidation-reduction potential Fc/Fc⁺ offerrocene was used as the reference potential, and the sweeping rate ofthe voltage was set to 0.5 V/s. When the measurement was performed usingelectrochemical analyzer Mode1660C, manufactured by ALS, as ameasurement apparatus, the first oxidation potentials estimated from theoxidation potential peaks of the example compounds A5 and AA9 were −1.05V and −1.00 V, respectively. Since those potentials are within the rangeof −1.20 to 0.00 V, the organic compounds each can simultaneouslysatisfy the stability against oxygen and the electron injectionperformance.

In addition, since having a low oxidation potential, the examplecompounds A5 and AA9 each have a high donor property, and when amaterial having a high acceptor property is mixed therewith, acharge-transfer complex can be formed. When this charge-transfer complexis used for the organic compound layer in contact with the electrode ofthe organic light emitting element, carrier injection from the electrodecan be easily performed.

On the other hand, after comparative compounds 3, 4, and 5 were left inthe air, when the oxidation potentials thereof were measured, anoxidation potential peak at approximately −1.00 V was not observed, andhence it was found that the intrinsic properties of the above compoundswere lost by oxidation. The comparative compound 3 is described inNon-Patent Literature 1 and is a compound in which a methyl group of 1-Aof this specification is substituted by a hydrogen atom. The comparativecompound 4 is described in Non-Patent Literature 1 and has the samestructure as that of 1-B of this specification. The comparative compound5 is described in Non-Patent Literature 2 and has the same structure asthat of 1-C of this specification.

In addition, Non-Patent Literature 1 has disclosed that the compound 1-Ais oxidized in the air and that the structure of the compound 1-B isrearranged by heat, and Non-Patent Literature 2 has disclosed that thecompound 1-C is oxidized in the air. Accordingly, it is found that thosecompounds are unstable compounds in the air. Hence, those compounds arematerials which are not suitably used for the organic light emittingelement.

In order to confirm the reactivity of the organic compound according tothe present disclosure with moisture in the air, the stability of eachof those compounds against water was investigated. After powders oflithium fluoride and cesium fluoride, each of which contains an alkalimetal, and a powder of the organic compound according to the presentdisclosure were left at room temperature and a high humidity of 95% for1 hour, the results obtained thereby were then compared to each other.The confirmation was performed by visual inspection, and the results areshown in Table 1.

TABLE 1 Molecular Structure Reactivity Example Compound A5

Not changed Example Compound AA9

Not changed Comparative LiF Slightly deliquesced Compound 1 ComparativeCsF Deliquesced Compound 2 Comparative Compound 3

Partially deliquesced and turned to black Comparative Compound 4

Partially deliquesced and turned to black Comparative Compound 5

Partially deliquesced and turned to brown

As shown in Table 1, the comparative compounds 1 to 5 deliquesced oroxidized.

On the other hand, the fulvalene compound according to the presentdisclosure was not changed, that is, for example, neither deliquescencenor oxidation occurred, and the stability thereof was confirmed.

The organic compound according to the present disclosure has asufficient electron injection property as the electron injectionmaterial and is a compound which is not likely to be oxidized in theair.

The reason the stability of the fulvalene compound according to thepresent disclosure is improved is considered as follows.

The fulvalene compound according to the present disclosure is a compoundin which the stability is improved by providing a bulky substituent foran unstable portion of a diazafulvalene skeleton.

First, the electron densities of portions of a dithiadiazafulvaleneskeleton and a dibenzodithiadiazafulvalene skeleton were estimated usingthe molecular orbital calculation. The calculation procedure is asdescribed below. For the calculation of the structures of molecules inthe electron ground state and in the electronically excited state,Gaussian 09, which is a commercially available electron statecalculation software, was used. In this case, as a quantum chemistrycalculation method, the density functional theory was employed, andB3LYP was used as the functional. As the base function, 6-31G* was used.

As shown in FIGS. 1A and 1B, the negative charge of the nitrogen atomwhich was considered to have a high activity was increased.Incidentally, the symmetric portions of the chemical structure had thesame value.

From the results described above, it is believed that the nitrogenatoms, each of which has the highest negative charge, of thedithiadiazafulvalene skeleton and the dibenzodithiadiazafulvaleneskeleton are responsible for the increase in instability.

The reason the comparative compounds 3, 4, and 5 are unstable in the airis believed that when an ethyl group, a benzyl group, or a methyl groupis only provided for the nitrogen atom having a high negative charge,the excluded volume effect is not sufficient, and hence, reactions withmoisture and/or oxygen in the air occur.

On the other hand, since having an aromatic hydrocarbon group or aheteroaromatic ring group, the fulvalene compound according to thepresent disclosure is a stable compound in the air.

In addition, it is found that the carbon atom adjacent to the sulfuratom of the dithiadiazafulvalene skeleton has a relatively largenegative charge. Hence, in order to further improve the stability, it ispreferable that a substituent having a large excluded volume asdescribed above is provided for this substitution position, or acondensed ring is formed together with this carbon atom. In this case,the formation of the condensed ring indicates the formation of a largerheteroaromatic ring, such as an imidazolium ring or a benzimidazoliumring. That is, when the dithiadiazafulvalene skeleton and thedibenzodithiadiazafulvalene skeleton are compared to each other, since acarbon atom having a relatively large negative charge is not present,the dibenzodithiadiazafulvalene skeleton is more preferable.

Those described above can also be applied to the case of adioxadiazafulvalene skeleton and a dibenzodioxadiazafulvalene skeleton.

In addition, as a method for further improving the stability of theorganic compound according to the present disclosure, a method may beconsidered in which the bulk volume of a substituent provided for thenitrogen atom having a high activity is increased as much as possible soas to increase the excluded volume. As a method to increase the excludedvolume, for example, the increase in number of carbon atoms of Ar₁ toAr₄ and the introduction of bulky substituents to Ar₁ to Ar₄ may bementioned.

However, when the number of carbon atoms of Ar₁ to Ar₄ is increased,although the excluded volume is increased, since the intermolecularstacking is increased, the sublimation property may be degraded in somecases. Hence, the excluded volume effect is preferably enhanced byproviding substituents for Ar₁ to Ar₄. That is, in view of the excludedvolume and the sublimation property, Ar₁ to Ar₄ are each preferably anaromatic hydrocarbon group having a relatively small molecular weight,such as 6 to less than 12 carbon atoms, or a heteroaromatic ring grouphaving 6 to less than 12 carbon atoms and each preferably have at leastone substituent.

As another method to improve the stability, a method in which anelectron-withdrawing substituent is introduced may be mentioned. As theelectron-withdrawing substituent, for example, a halogen atom, such as afluorine atom, a cyano group, or a heteroaromatic ring group having anelectron-withdrawing nitrogen atom may be mentioned. When at least oneof those substituents is provided for at least one of Ar₁ to Ar₄ and R₁to R₄, the oxidation potential of the organic compound becomes higher,and the difference thereof from the reduction potential of oxygen isincreased; hence, it is preferable since the oxidation stability isimproved. In addition, in the case in which at least one of Ar₁ to Ar₄itself is a heteroaromatic ring group having an electron-withdrawingnitrogen atom, it is also preferable since the effect similar to thatdescribed above can be obtained.

As described above, by the use of a fulvalene compound having a lowoxidation potential as the electron injection layer, a stable elementhaving a high stability against water as compared to that obtained byusing an alkali metal salt or an alkali metal can be provided.

By analysis of the organic compound layer of the organic light emittingelement using time-of-flight secondary mass spectrometry (TOF-SIMS) orthe like, whether the organic light emitting element contains theorganic compound according to the present disclosure or not can beconfirmed. The above analytical method is simply described by way ofexample, and a method in which after the organic compound is extractedfrom the organic light emitting element, analysis is performed usinginfrared rays (IR), ultraviolet rays (UV), nuclear magnetic resonance(NMR), or the like may also be performed.

(Examples of Fulvalene Compound According to Present Disclosure)

Hereinafter, concrete structural formulas of a dithiadiazafulvalenecompound, a dioxadiazafulvalene compound, a dibenzodithiadiazafulvalenecompound, a dibenzodioxadiazafulvalene compound, abenzodithiadiazafulvalene compound, and a benzodioxadiazafulvalenecompound will be shown by way of example. However, the presentdisclosure is not limited to those concrete examples. In this case,“iPro” represents an iso-propyl group, and “tBu” represents a tert-butylgroup.

Among the compounds shown by way of example, the compounds shown in thegroup A and the group AA are compounds each of which has as Ar₁ to Ar₄of the formulas [1] and [2], a phenyl group with or without at least onesubstituent or a naphthyl group with or without at least onesubstituent. Since a phenyl group or a naphthyl group is an aromatichydrocarbon group having a relatively low molecular weight, inparticular, the sublimation property is excellent. In addition, as shownin FIGS. 1A and 1B, when the group A and the group AA are compared toeach other, since no carbon atom having a relatively large negativecharge is present in the group AA, the group AA is superior in terms ofthe stability.

That is, the compounds shown in the group A and the group AA arecompounds having stability against oxidation and an excellentsublimation property.

Among the compounds shown by way of example, the compounds shown in thegroup B and the group BB are compounds each of which has as Ar₁ to Ar₄of the formulas [1] and [2], an aromatic hydrocarbon group having 12 toless than 24 carbon atoms with or without at least one substituent.Since the aromatic hydrocarbon group has a relatively high molecularweight, the vicinity of the nitrogen atom of the base skeleton iscovered with a bulkier aromatic ring, and hence, in particular, theoxidation stability is excellent. In addition, as shown in FIGS. 1A and1B, when the group B and the group BB are compared to each other, sinceno carbon atom having a relatively large negative charge is present inthe group BB, the group BB is superior in terms of the stability.

That is, the compounds shown in the group B and the group BB areparticularly superior compounds in terms of the oxidation stability dueto the excluded volume effect.

Among the compounds shown by way of example, the compounds shown in thegroup C and the group CC are compounds each of which has as Ar₁ to Ar₄of the formulas [1] and [2], a heteroaromatic ring group with or withoutat least one substituent. Since the heteroaromatic ring group ispresent, the nitrogen atom of the base skeleton has the stability notonly by the excluded volume effect described above but also by theelectronic influence. In addition, as shown in FIGS. 1A and 1B, when thegroup C and the group CC are compared to each other, since no carbonatom having a relatively large negative charge is present in the groupCC, the group CC is superior in terms of the stability.

That is, the compounds shown in the group C and the group CC areparticularly superior compounds in terms of the stability due to theelectronic effect.

Among the compounds shown by way of example, the compounds shown in thegroup D are the compounds having an asymmetric structure. In this case,the symmetric structure indicates that as shown in FIG. 2, the symmetricplanes are each present in a direction perpendicular to the molecularplane shown by a dotted line. On the other hand, in a molecule having anasymmetry structure and a low symmetric property as shown in the rightside of FIG. 2, the molecular arrangement is liable to be disordered inthin film formation, and hence, the molecular packing is suppressed, andamorphous properties are enhanced.

That is, the compounds shown in the group D are compounds each of whichimparts an excellent film quality in thin film formation.

(Synthesis Method of Fulvalene Compound According to Present Disclosure)

Next, a synthesis method of the fulvalene compound according to thepresent disclosure will be described.

As the organic compound according to the present disclosure, forexample, a dithiadiazafulvalene compound may be synthesized inaccordance with the following synthesis scheme. In this case, P₁ to P₃each represent a substituent to be introduced.

In particular, by sequentially performing the following reactions (1) to(3), the dithiadiazafulvalene compound is synthesized.

(1) A sulfide forming reaction by carbon disulfide and a cyclizationreaction by an acid(2) An oxidation reaction by hydrogen peroxide and an acid(3) A reaction forming a carbene and an olefin by a strong base

In addition, a dioxadiazafulvalene compound may be synthesized inaccordance with the following synthesis scheme. In this case, P₄ to P₆each represent a substituent to be introduced.

In particular, by sequentially performing the following reactions (4) to(7), the dioxadiazafulvalene compound is synthesized.

(4) A dehydration condensation reaction by an acid(5) A formylation reaction by acetic formic anhydride(6) A cyclization reaction by trifluoroacetic anhydride(7) A reaction forming a carbene and an olefin by a strong base

In addition, a dibenzodithiadiazafulvalene compound may be synthesizedin accordance with the following synthesis scheme. In this case, P₇ andP₈ each represent a substituent to be introduced.

In particular, by sequentially performing the following reactions (8) to(11), the dibenzodithiadiazafulvalene compound is synthesized.

(8) A coupling reaction by a Pd catalyst(9) A thiol formation reaction(10) A cyclization reaction by an acid(11) A reaction forming a carbene and an olefin by a strong base

In addition, a dibenzodioxadiazafulvalene compound may be synthesized inaccordance with the following synthesis scheme. In this case, P₉ and P₁₀each represent a substituent to be introduced.

In particular, by sequentially performing the following reactions (12)to (15), the dibenzodioxadiazafulvalene compound is synthesized.

(12) A coupling reaction by a Pd catalyst(13) A phenol formation reaction(14) A cyclization reaction by an acid(15) A reaction forming a carbene and an olefin by a strong base

(Organic Electronic Element According to Embodiment)

An organic electronic element according to this embodiment is an organicelectronic element having a pair of electrode and an organic compoundlayer disposed therebetween and is an organic electronic elementcharacterized in that the organic compound layer is formed of theorganic compound represented by the general formula [1].

As the organic electronic element according to this embodiment, forexample, an organic light emitting element, an organic transistor, or anorganic solar cell may be mentioned. The organic compound layer may beformed of a single layer or a plurality of layers, and the organiccompound represented by the general formula [1] may be used for anylayer of the organic compound layer.

The organic light emitting element according to this embodiment is anorganic light emitting element having an anode, a cathode, and a lightemitting layer disposed therebetween and has an organic compound layerbetween the cathode and the light emitting layer, and this organiccompound layer is formed of the organic compound represented by thegeneral formula [1]. The organic compound layer is preferably in contactwith the cathode.

In the organic light emitting element of this embodiment, at least onelayer disposed between the cathode and the light emitting layer containsthe fulvalene compound according to the present disclosure.

In this case, the organic compound layer disposed between the cathodeand the light emitting layer is also called an electron transport layeror an electron injection layer, and in particular, the organic compoundlayer in contact with the cathode is also called an electron injectionlayer.

As the element structure of the organic light emitting element accordingto this embodiment, an element structure having the following organiccompound layers on a substrate may be mentioned. Among the organiccompound layers, a layer containing a light emitting material is thelight emitting layer. The organic compound layer may be formed of asingle layer or a plurality of layers.

The organic light emitting element according to this embodiment mayhave, besides the light emitting layer, a hole injection layer, a holetransport layer, an electron blocking layer, a hole blocking layer, anelectron transport layer, an electron injection layer, and the like. Inaddition, the light emitting layer may be either a single layer or alaminate formed of a plurality of layers.

As the structure of the organic light emitting element, for example, thefollowing structures may be mentioned.

(1) anode/light emitting layer/cathode(2) anode/hole transport layer/light emitting layer/electron transportlayer/cathode(3) anode/hole transport layer/light emitting layer/electron transportlayer/electron injection layer/cathode(4) anode/hole injection layer/hole transport layer/light emittinglayer/electron transport layer/cathode(5) anode/hole injection layer/hole transport layer/light emittinglayer/electron transport layer/electron injection layer/cathode(6) anode/hole transport layer/electron blocking layer/light emittinglayer/hole blocking layer/electron transport layer/cathode

However, those examples of the element structure are quite basic elementstructures, and the structure of the organic light emitting elementusing the compound according to the present disclosure is not limitedthereto.

In addition, among the above element structures, the structure (6)having both the electron blocking layer and the hole blocking layer ispreferably used. In the structure (6), since both carriers, that is,holes and electrons, can be confined in the light emitting layer, alight emitting element having no carrier leakage and a high lightemission efficiency can be obtained.

In addition, various layer structures may be formed, that is, forexample, an insulating layer is provided on the interface between theelectrode and the organic compound layer, an adhesive layer or aninterference layer is provided, the electron transport layer or the holetransport layer is formed of two layers having different ionizationpotentials, and the light emitting layer is formed of two layer usingdifferent light emitting materials.

The organic light emitting element according to this embodiment may beeither a bottom emission type in which light is extracted from anelectrode at a substrate side or a top emission type in which light isextracted from a side opposite to the substrate, and may also be used asa double-side extraction structure.

In the organic light emitting element according to this embodiment,although the organic compound layer disposed between the cathode and thelight emitting layer contains the organic compound represented by thegeneral formula [1], the organic compound represented by the generalformula [1] may also be used for another organic compound layer.

In particular, the fulvalene compound according to the presentdisclosure may be contained in any one of the hole injection layer, thehole transport layer, the electron blocking layer, the hole blockinglayer, the electron transport layer, the electron injection layer, andthe like. The organic compound according to this embodiment ispreferably contained in the electron injection layer.

The organic compound according to the present disclosure may be usedalone but is preferably used together with a different type compounddifferent therefrom. The different type compound different from theorganic compound according to the present disclosure is a compounddifferent from the fulvalene compound represented by the general formula[1].

The weight rate of the different type compound is preferably more than 0to 80 percent by weight when the total of the organic compound layerdisposed between the cathode and the light emitting element layer isassumed to be 100 percent by weight. For example, the case in which theelectron transport layer and the electron injection layer are providedbetween the cathode and the light emitting layer will be described byway of example. When the total of the electron injection layer isassumed to be 100 percent by weight, the weight rate of the differenttype compound different from the organic compound layer according to thepresent disclosure is more than 0 to 80 percent by weight. The electrontransport layer is not included in the total. In addition, when thetotal of the organic compound according to the present disclosure andthe different type compound is assumed to be 100 percent by weight, theweight rate of the different type compound may be more than 0 to 80percent by weight.

When the organic compound layer of the organic light emitting element isanalyzed using TOF-SIMS or the like, the weight rate of the compound canbe obtained, and whether the organic light emitting element has theorganic compound according to the present disclosure or not can beconfirmed. The above analysis is described by way of example, and amethod may also be used in which after the organic compound is extractedfrom the organic light emitting element, analysis is performed using IR,UV, NMR, or the like.

The different type compound is preferably a compound having a highoxidation potential as compared to that of the organic compoundaccording to the present disclosure.

The different type compound is preferably one of an anthraquinonederivative, a fluorene derivative, a naphthalene derivative, an indenederivative, a terphenyl derivative, an acenaphthofluoranthenederivative, an indenoperylene derivative, and a phenanthrolinederivative.

The light emitting layer of the organic light emitting element accordingto this embodiment may be formed of at least two types of components,and the components may be categorized into a primary component and anauxiliary component. The primary component is a compound having themaximum weight rate among all the compounds forming the light emittinglayer and may be called a host material. The host material is a compoundpresent as a matrix around a guest material in the light emitting layerand is a compound primarily responsible to transport carriers and toimpart excited energy to the guest material.

The auxiliary component is a compound other than the primary component.The auxiliary component may be called a guest material, a light emittingassist material, or a charge injection material. The guest material mayalso be called a dopant material. The light emitting assist material andthe charge injection material may be either organic compounds having thesame structure or organic compounds having different structures.Although functioning as the auxiliary components, those organiccompounds may also be called a host material 2 so as to be distinguishedfrom the guest material.

In this case, the guest material is a compound primarily responsible forlight emission in the light emitting layer.

When the total of the compounds forming the light emitting layer isassumed to be 100 percent by weight, the concentration of the guestmaterial is 0.01 to less than 50 percent by weight and preferably 0.1 to20 percent by weight. In order to suppress the concentration quenching,the concentration of the guest material is more preferably 10 percent byweight or less. In addition, the guest material may be uniformlycontained in the whole layer formed of the host material, may becontained to have a concentration gradient, or may be containedpartially in a specific region so as to form a region of the hostmaterial layer in which no guest material is contained.

This light emitting layer may be formed of either a single layer or aplurality of layers, and when light emitting materials having at leasttwo types of light emission colors are contained, a mixed color may beemitted. In the case of using a plurality of layers, the light emittinglayer may be laminated with a light emitting layer different therefrom.In this case, the light emission color of the organic light emittingelement is from blue to green or red but is not particularly limitedthereto.

In more particular, the light emission color may be either white orintermediate color. In the case of the white, by respective lightemitting layers, red, blue, and green are emitted. In addition, the filmformation may be performed by a deposition or a coating method.

In the organic light emitting element according to this embodiment, alight emitting portion may contain a plurality of types of lightemitting materials. Any two out of the plurality of types of lightemitting materials emit different types of light, and an elementincluding those light emitting materials may be an element emittingwhite color.

In addition, the organic light emitting element according to thisembodiment may be an organic light emitting element in which a pluralityof light emitting layers is provided, at least one of the light emittinglayers is a light emitting layer emitting light having a wavelengthdifferent from that of the rest of the light emitting layers, and thosedifferent types of light of the light emitting layer are mixed with eachother to emit white light. In the case in which a plurality of lightemitting layers is provided, the plurality of light emitting layers maybe laminated to each other or arranged side by side. The “arranged sideby side” indicates that the light emitting layers are each in contactwith the hole transport layer, the electron transport layer, or theelectrode adjacent thereto.

When the plurality of light emitting layers are laminated to each other,the light emitting layers may be in contact with each other, or anothercompound layer may be provided between the light emitting layers. Theanother compound layer may be a charge generation layer or the like.

Besides the organic compound according to this embodiment, if needed,for example, a low molecular weight-based or a high molecularweight-based light emitting material, a hole injection compound or ahole transport compound, a compound to be used as a host, a lightemitting compound, and an electron injection compound or an electrontransport compound, each of which has been known, may also be usedtogether.

Hereinafter, examples of those compounds will be described.

As the hole injection/transport material, a material having a high holemobility is preferable so that a hole from the anode can be easilyinjected and a hole thus injected is transported to the light emittinglayer. In addition, in order to suppress the degradation in filmquality, such as crystallization, in the organic light emitting element,a material having a high glass transition temperature is preferable. Asa low molecular weight and a high molecular weight material having ahole injection/transport ability, for example, there may be mentioned atriarylamine derivative, an arylcarbazole derivative, a phenylenediaminederivative, a stilbene derivative, a phthalocyanine derivative, aporphyrin derivative, a polyvinylcarbazole, a polythiophene, and otherelectrically conductive polymers. Furthermore, the holeinjection/transport material described above is also preferably used forthe electron blocking layer.

Hereinafter, although concrete examples of the compounds to be used asthe hole injection/transport material will be shown below, the compoundsare not limited thereto.

As a light emitting material primarily relating to the light emissionfunction, for example, there may be mentioned a condensed ring compound(such as a fluorene derivative, a naphthalene derivative, a pyrenederivative, a perylene derivative, a tetracene derivative, an anthracenederivative, and a rubrene derivative), a quinacridone derivative, acumarin derivative, a stilbene derivative; an organic aluminum complex,such as tris(8-quinolinolato) aluminum; an iridium complex, a platinumcomplex, a rhenium complex, a copper complex, an europium complex, aruthenium complex, and a high molecular weight derivative, such as apoly(phenylene vinylene) derivative, a polyfluorene derivative, and apolyphenylene derivative.

Hereinafter, although concrete examples of the compounds to be used asthe light emitting material will be shown below, the compounds are notlimited thereto.

As a light emitting-layer host or a light emitting assist materialcontained in the light emitting layer, for example, besides an aromatichydrocarbon compound and the derivatives thereof, a carbazolederivative, a dibenzofuran derivative, a dibenzothiophene derivative, anorganic aluminum complex, such as tris(8-quinolinolato) aluminum, and anorganic beryllium complex may be mentioned.

Hereinafter, although concrete examples of the compounds to be used asthe light emitting-layer host or the light emitting assist materialcontained in the light emitting layer will be shown below, the compoundsare not limited thereto.

As the electron transport material, any material capable of transportingelectrons injected from the cathode to the light emitting layer may beselected in consideration of, for example, the balance with the holemobility of the hole transport material. As the material having anelectron transport ability, for example, there may be mentioned anoxadiazole derivative, an oxazole derivative, a pyrazine derivative, atriazole derivative, a triazine derivative, a quinoline derivative, aquinoxaline derivative, a phenanthroline derivative, an organic aluminumcomplex, and a condensed ring compound (such as a fluorene derivative, anaphthalene derivative, a chrysene derivative, or an anthracenederivative). Furthermore, the above electron transport material is alsopreferably used for the hole blocking layer.

Hereinafter, concrete examples of the compounds to be used as theelectron transport material will be shown below, but the compounds arenot limited thereto.

As the electron injection material, any material capable of easilyperforming electron injection from the cathode may be selected inconsideration of, for example, the balance with the hole injectionproperty. A bis(benzoimidazole-2-ilydene) compound having an alkylcross-linking shown in this embodiment by way of example may also beused by mixing with the electron transport material. In addition, thecompound described above may also be used by mixing with a materialcontaining a cyano group, a fluorine atom, or a fluoranthene skeleton ora material containing a condensed ring structure. In this case,“material containing a fluoranthene skeleton” indicates a materialhaving a fluoranthene structure in its chemical structure. Among theexample compounds described in this embodiment, ET10, EI6, EI7, EI8,EI9, EI12, EI14, EI15, EI16, EI17, EI18, and EI19 may be mentioned.

A material forming the anode preferably has a high work function as muchas possible. For example, there may be used a metal element, such asgold, platinum, silver, copper, nickel, palladium, cobalt, selenium,vanadium, or tungsten; a mixture containing the metal mentioned above;an alloy formed from the metal mentioned above; or a metal oxide, suchas tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), orindium zinc oxide. In addition, an electrically conductive polymer, suchas a polyaniline, a polypyrrole, or a polythiophene, may also be used.

Those electrode materials may be used alone, or at least two typesthereof may be used in combination. In addition, the anode may be formedof either a single layer or a plurality of layers.

On the other hand, as a material forming the cathode, a material havinga low work function is preferable. For example, an alkali metal, such aslithium, an alkaline earth metal, such as calcium, a metal element, suchas aluminum, titanium, manganese, silver, lead, or chromium, or amixture containing the above metal may be mentioned. In addition, analloy formed by combination of the metals mentioned above may also beused. For example, magnesium-silver, aluminum-lithium,aluminum-magnesium, silver-copper, or zinc-silver may be used. A metaloxide such as indium tin oxide (ITO) may also be used. Those electrodematerials may be used alone, or at least two types thereof may be usedin combination. In addition, the cathode may be formed of either asingle layer or a plurality of layers.

The organic compound layers (such as the hole injection layer, the holetransport layer, the electron blocking layer, the light emitting layer,the hole blocking layer, the electron transport layer, and the electroninjection layer) forming the organic light emitting element according tothis embodiment are formed by the methods shown below.

The organic compound layers forming the organic light emitting elementaccording to this embodiment may be formed by using a dry process, suchas a vacuum deposition method, an ionization deposition method,sputtering, or plasma CVD. In addition, instead of using a dry process,a wet process may also be used which forms a layer by a known coatingmethod (such as spin coating, dipping, a casting method, an LB method,or an inkjet method) using a solution containing an appropriate solventand an organic compound.

In this case, when the layer is formed by a vacuum deposition method, asolution coating method, or the like, for example, crystallization isnot likely to occur, and hence the aging stability is excellent. Inaddition, when the film is formed by a coating method, the film may beformed in combination with an appropriate binder resin.

As the binder resin mentioned above, although a poly(vinyl carbazole)resin, a polycarbonate resin, a polyester resin, an ABS resin, anacrylic resin, a polyimide resin, a phenol resin, an epoxy resin, asilicone resin, or a urea resin may be mentioned, the binder resin isnot limited thereto.

In addition, as the binder resin, homopolymers or copolymers may be usedalone, or at least two types thereof may be used in combination.Furthermore, if needed, additives, such as a known plasticizer,antioxidant, and UV absorber, may also be used together therewith.

(Application of Organic Light Emitting Element According to Embodiment)

The organic light emitting element according to this embodiment may beused as a constituent member of a display device or a lighting device.Furthermore, the organic light emitting element described above may alsobe applied to, for example, an exposure light source of anelectrophotographic image forming device, a backlight of a liquidcrystal device, or a light emitting device having a color filterprovided for a white light source. As the color filter, for example, afilter which allows one of three colors, red, green, and blue, to passtherethrough may be mentioned.

The display device according to this embodiment has a plurality ofpixels, and at least one of those pixels has the organic light emittingelement according to this embodiment. In addition, this pixel has theorganic light emitting element according to this embodiment and anactive element. As the active element, a switching element or anamplifier element may be mentioned, and in particular, a transistor maybe mentioned. The anode or the cathode of this organic light emittingelement is electrically connected to a drain electrode or a sourceelectrode of the transistor. The transistor may have an oxidesemiconductor in its active region. The oxide semiconductor may beeither amorphous or crystalline or may be a mixture thereof. The crystalmay be any one of a single crystal, a fine crystal, and a crystal inwhich a specific axis, such as the C axis, is oriented, or may be amixture containing at least two crystals mentioned above.

The organic light emitting device having the switching element asdescribed above may also be used as an image display device in which theorganic light emitting elements are each provided as the pixel or mayalso be used as a lighting device. In addition, the organic lightemitting device described above may also be used as an exposure lightsource exposing a photoreceptor of an electrophotographic type imageforming device, such as a laser printer or a copying machine.

In this case, the display device may be used as an image display deviceof a personal computer (PC) or the like. As the transistor describedabove, for example, a thin film transistor (TFT) element may bementioned, and this TFT element is provided, for example, on aninsulating surface of a substrate.

The display device may be an image information processing device whichhas an image input portion inputting image information from an areacharge coupled device (CCD), a linear CCD, a memory card, or the like,an information processing portion processing input information, and adisplay portion displaying an input image.

In addition, the display portion of an image taking device or an inkjetprinter may have a touch panel function. A drive method of this touchpanel function may be any one of an infrared method, an electrostaticcapacitance method, a resistive membrane method, and an electromagneticinduction method but is not particularly limited.

In addition, the display device may be used for a display portion of amultifunctional printer.

The lighting device is a device lighting the inside of a room. Thelighting device may be a device emitting any one of white color (colortemperature: 4,200K), neutral white color (color temperature: 5,000K),and other colors from blue to red. Among organic light emitting elementsof the lighting device, any one of the organic light emitting elementsmay be the organic light emitting element of the present disclosure.

The lighting device according to this embodiment has the organic lightemitting element according to this embodiment and an AC/DC converterconnected thereto. The AC/DC converter is a circuit converting analternating current voltage to a direct current voltage. This converteris a circuit to supply a drive voltage to the organic light emittingelement. In addition, this lighting device may further have a colorfilter.

In addition, the lighting device according to this embodiment may have aheat dissipation portion. The heat dissipation portion functions todissipate heat in the device to the outside thereof and may be formed ofa metal having a high specific heat, liquid silicon, or the like.

The image forming device according to this embodiment is an imageforming device having a photoreceptor, an exposure portion exposing thisphotoreceptor, a charging portion charging this photoreceptor, and adeveloping portion imparting a developer to the photoreceptor. In thiscase, the exposure portion of the image forming device has a pluralityof the organic light emitting elements of the present disclosure. As thedeveloper, toner, ink, or the like may be mentioned. The toner may beeither a dry toner or a liquid toner.

In addition, the organic light emitting element according to thisembodiment may be used as a constituent member of an exposure deviceexposing a photoreceptor. An exposure device having the organic lightemitting element according to this embodiment has a plurality of lightemitting points, and at least any one of the light emitting pointsdescribed above has the organic light emitting element according to thisembodiment. Those light emitting points are aligned along a long axisdirection of the photoreceptor.

Next, with reference to the drawings, the display device according tothis embodiment will be described. FIG. 3 is a schematic cross-sectionalview showing one example of a display device having an organic lightemitting element and a TFT element connected thereto. The TFT element isone example of the active element.

A display device 1 shown in FIG. 3 includes a substrate 11 formed ofglass or the like and a moistureproof film 12 provided thereon toprotect the TFT element or the organic compound layer. In addition,reference numeral 13 indicates a gate electrode formed of a metal.Reference numeral 14 indicates a gate insulating film, and referencenumeral 15 indicates a semiconductor layer.

A TFT element 18 has the semiconductor layer 15, a drain electrode 16,and a source electrode 17. On the TFT element 18, an insulating film 19is provided. Through a contact hole 20, an anode 21 forming the organiclight emitting element and the source electrode 17 are connected to eachother.

In addition, the method for electrical connection between the electrodes(the anode and the cathode) of the organic light emitting element andthe electrodes (the source electrode and the drain electrode) of the TFTis not limited to the mode shown in FIG. 3. That is, any one of theanode and the cathode and any one of the source electrode and the drainelectrode of the TFT element may be electrically connected to eachother.

In the display device 1 shown in FIG. 3, although the organic compoundlayer is shown as if formed of one layer, an organic compound layer 22may be formed of a plurality of layers. On a cathode 23, a firstprotective layer 24 and a second protective layer 25, each of whichsuppresses the degradation of the organic light emitting element, areprovided.

In the display device 1 shown in FIG. 3, although the transistor is usedas a switching element, instead of using the transistor, ametal-insulator-metal (MIM element) may also be used as a switchingelement.

In addition, the transistor used in the display device 1 shown in FIG. 3is not limited to a transistor using a single crystal silicon wafer butmay be a thin film transistor having an active layer on an insulatingsurface of a substrate. As the active layer, for example, single crystalsilicon, non-single crystal silicon, such as amorphous silicon or finecrystal silicon, or a non-single crystal oxide semiconductor, such asindium zinc oxide or indium gallium zinc oxide, may be mentioned. Inaddition, the thin film transistor is also called a TFT element.

The transistor included in the display device 1 shown in FIG. 3 may beformed in the substrate, such as a Si substrate. In this case, “beingformed in the substrate” indicates the case in which the transistor isformed by machining the substrate itself, such as a Si substrate. Thatis, the transistor provided in the substrate may also be considered thatthe substrate and the transistor are integrally formed.

Whether the transistor is provided in the substrate or not may beselected in consideration of the definition. For example, the case inwhich the definition per inch is approximately equal to that of QVGA,the transistor is preferably provided in a Si substrate.

FIG. 4 is a schematic view of an image forming device 26 according tothe present disclosure. The image forming device has a photoreceptor, anexposure light source, a developing portion, a charging portion, atransfer unit, a transport roller, and a fixing unit.

Light 29 is emitted from an exposure light source 28, and anelectrostatic latent image is formed on the surface of a photoreceptor27. This exposure light source 28 has the organic light emitting elementaccording to the present disclosure. A developing portion 30 has toneror the like. A charging portion 31 charges the photoreceptor 27. Atransfer unit 32 transfers a developed image onto a recording medium 34.A transport roller 33 transports the recording medium 34. The recordingmedium 34 is for example, paper. A fixing unit 35 fixes an image formedon the recording medium 34.

FIG. 5 is a schematic view showing the exposure light source 28 in whicha plurality of light emitting portions 36 is disposed on a longsubstrate. An arrow 37 indicates a column direction along which theorganic light emitting elements are arranged. This column direction isthe same direction as that of the axis around which the photoreceptor 27is rotated. This direction may also be called the long axis direction ofthe photoreceptor.

A part (a) of FIG. 5 shows the state in which the light emittingportions are arranged along the long axis direction of thephotoreceptor. A part (b) of FIG. 5 shows the state different from thatof the part (a) and the state in which the light emitting portions of afirst column and the light emitting portions of a second column arearranged intermittently along the column direction. The first column isarranged at a position different from that of the second column in therow direction.

In the first column, the light emitting portions are arranged withspaces provided therebetween. In the second column, the light emittingportions are arranged at positions corresponding to the spaces of thelight emitting portions of the first column. That is, in the rowdirection, the light emitting portions are also arranged with spacestherebetween.

The arrangement of the part (b) of FIG. 5 may also be called a latticearrangement, a stagger arrangement, or a checkered pattern arrangement.

FIG. 6 is a schematic view of the lighting device according to thepresent disclosure. The lighting device has a substrate, an organiclight emitting element 38, and an AC/DC converter 39. The lightingdevice may also have a switching element connected to the organic lightemitting element. In addition, a heat dissipation portion not shown inthe drawing may also be provided, for example, at a rear surface sideopposite to the substrate surface on which the organic light emittingelement is provided.

As described above, when the display device, the lighting device, andthe image forming device, each of which uses the organic light emittingelement of the present disclosure, is driven, an excellent image qualitycan be obtained, and a long and stable operation can be performed.

FIG. 7 is a schematic view showing one example of an organicphotoelectric conversion element according to this embodiment.

The organic photoelectric conversion element according to thisembodiment has an anode 44, a cathode 43, and an organic photoelectricconversion layer 40 provided therebetween. A second organic compoundlayer 41 may be provided between the cathode 43 and the organicphotoelectric conversion layer 40, and the second organic compound layermay contain the organic compound according to the present disclosure. Athird organic compound layer 42 may be provided between the anode 44 andthe organic photoelectric conversion layer 40. The third organiccompound layer may contain the organic compound according to the presentdisclosure. The anode 44 or the cathode 43 is connected to a readingcircuit 45. The reading circuit 45 reads information based on the chargegenerated in the organic photoelectric conversion layer 40 and, forexample, transmits the information to a signal processing circuit (notshown) provided at a latter stage. The reading circuit 45 includes, forexample, a transistor which outputs a signal based on the chargegenerated in the organic photoelectric conversion layer.

An inorganic protective layer 46 is disposed on the cathode 43. Theinorganic protective layer 46 may be formed by a sputtering method, avacuum deposition method, an aluminum layer deposition (ALD) method, orthe like using aluminum oxide, silicon oxide, silicon nitride, or thelike.

On the inorganic protective layer 46, a color filter 47 is disposed. Thecolor filter may form a Bayer arrangement in combination with colorfilters of adjacent organic photoelectric conversion elements.

On the color filter 47, a microlens 48 is disposed. The microlenscondenses incident light on the organic photoelectric conversion layer.

The organic photoelectric conversion element according to thisembodiment may be used for an image taking element. The image takingelement has a plurality of pixels and a signal processing portionconnected thereto.

In a pixel including the organic photoelectric conversion element, adifferent type of organic photoelectric conversion element performingphotoelectric conversion of different color light may be furtherprovided. The different type of organic photoelectric conversion elementis laminated on the organic photoelectric conversion element. Thedifferent type of organic photoelectric conversion element is an elementperforming photoelectric conversion of light in a different wavelengthregion, and when those elements are used in combination, an image takingelement may be formed without providing the color filter.

The organic photoelectric conversion element according to thisembodiment may be used for an image taking element. The image takingelement includes a plurality of pixels and a signal processing portion.At least one pixel includes the organic photoelectric conversion elementaccording to this embodiment and a reading circuit connected thereto.The plurality of pixels are arranged in a matrix containing a pluralityof rows and a plurality of columns. In the structure as described above,a signal is output from each pixel as one pixel signal, so that an imagesignal can be obtained.

The pixel may also have a color filter at a light incident side. As thecolor filter, a color filter which transmits specific light, such as redlight, may be mentioned. One pixel may be provided for one color filter.

The pixel may have a microlens at a light incident side. The microlensis a lens condensing light on the photoelectric conversion layer.

When the organic photoelectric conversion element according to thisembodiment is used for an image taking element, an optical filter may beprovided at a light incident side of the image taking element. As theoptical filter, for example, a low-pass filter, a UV-cut filter cuttinglight having a wavelength of UV rays or less, an IR-cut filter cuttinginfrared rays may be mentioned. By the use of those optical filters,noises are reduced, and hence an image having a high image quality canbe obtained.

The organic photoelectric conversion element according to thisembodiment may be used for an image taking device. The image takingdevice has an image taking optical system and an image taking elementreceiving light passing through the image taking optical system.

The image taking device may further have a receiving portion receiving asignal from the outside or a transmitting portion transmitting anobtained image to the outside. The signal received by the receivingportion may be a signal controlling at least one of an image takingrange of the image taking device, the start of image taking, and thestop of image taking.

A method in which the image taking device communicates with the outsidemay be either a wired method or a wireless method.

As has thus been described, the organic compound according to thepresent disclosure may be used for the organic photoelectric conversionelement. The organic photoelectric conversion element according to thisembodiment is an organic photoelectric conversion element in which adark current is suppressed, and when this element is used for an imagetaking element, an image taking element having a high resolution can beprovided.

EXAMPLES Example 1 Synthesis of Example Compound A1

(1) Synthesis of Compound D3

The following reagent and solvents were charged into a 50-ml eggplantflask.

D1: 3.00 g (16.9 mmol)

DMSO: 10 ml

20 N NaOH aqueous solution: 0.8 ml

Next, the reaction solution was cooled to 0° C. while being stirred in anitrogen atmosphere. Subsequently, 1.0 ml (16.9 mmol) of carbondisulfide was slowly dripped and was then stirred at 0° C. for 30minutes. Next, stirring was performed at room temperature for 1 hour.The solution was again cooled to 0° C., and 1.7 ml (16.9 mmol) of D2 wasslowly dripped and was then stirred at 0° C. for 30 minutes.Subsequently, stirring was performed at room temperature for 1 hour.After the reaction was completed, water was added to the reactionsolution and then stirred, and filtration thereof was performed using amembrane filter, so that a residue was obtained. After the residue thusobtained was dissolved in 20 ml of ethanol, 0.85 ml of a conc.hydrochloric acid was added, and heat reflux was performed for 1 hourwhile stirring was performed in a nitrogen atmosphere. After thereaction was completed, the reaction solution was cooled to roomtemperature, and a precipitated white solid was filtrated. A residue wasre-crystallized using ethanol, so that 3.81 g (yield: 74%) of D3 wasobtained.

(2) Synthesis of Compound D4

The following reagents and solvent were charged into a 50-ml eggplantflask.

D3: 1.00 g (3.27 mmol)Acetic acid: 10 mlHydrogen peroxide solution: 1 ml

Next, the reaction solution was stirred at room temperature in anitrogen atmosphere for 2 hours. After the reaction was completed, thereaction solution was concentrated under a reduced-pressure condition,so that a residue was obtained. To this residue, 20 ml of water and 0.7ml of HBF₄ were added, and stirring was performed at room temperaturefor 1 hour. A precipitated pale yellow solid was filtrated, so that acrude product was obtained. Next, this crude product was purified usinga silica gel column chromatography (eluent: chloroform/ethanol=200/1 to50/1) and was then processed by dispersion washing using a diethyl ethersolvent, so that 0.90 g (yield: 76%) of D4 in the form of white solidwas obtained.

(3) Synthesis of Example Compound A1

The following reagent and solvent were charged into a 50-ml eggplantflask in a nitrogen flow atmosphere.

D4: 470 mg (1.30 mmol)

Dehydrated DMF: 10 ml

After this solution was deaerated using nitrogen, 187 mg (3.90 mmol) ofsodium hydride (oil dispersion at 50% to 60%) was charged thereto, andstirring was then performed for 2 minutes. Subsequently, 145 mg (1.30mmol) of potassium tert-butoxide was added, and stirring was performedat room temperature for 6 hours. After the reaction was completed, whilestirring was performed, 30 ml of water which was deaerated usingnitrogen was slowly added to precipitate a target product, and thesolvent was then removed using a syringe. Next, after the operation ofadding 20 ml of water deaerated using nitrogen and removing the solventusing a syringe was again performed twice, 10 ml of hexane deaeratedusing nitrogen was added, and dispersion washing was performed by anultrasonic washing machine. Subsequently, after filtration was performedusing a membrane filter, and a residue was washed with hexane deaeratedusing nitrogen, drying was performed at 50° C. under a reduced-pressurecondition, so that 181 mg (yield: 51%) of the example compound A1 in theform of red powder was obtained.

The example compound A1 thus obtained was identified by the followingmethod.

[Matrix assisted laser desorption/ionization-time of flight-massspectroscopy (MALDI-TOF-MS) (Autoflex LRF manufactured by Bruker)]Measured value: m/z=546.50, calculated value: C₃₄H₄₆N₂S₂=546.87

By CV measurement under the following conditions, the first oxidationpotential was −1.05 V.

The CV measurement was performed in an N,N-dimethylformamide solution of0.1 M tetrabutylammonium perchlorate. The measurement was performedunder the conditions in which Ag/Ag⁺, Pt, and glassy carbon were usedfor the reference electrode, the counter electrode, and the workingelectrode, respectively, the oxidation reduction potential Fc/Fc⁺ offerrocene was used as the reference potential, and the sweeping rate ofthe voltage was set to 0.5 V/s. The measurement was performed usingelectrochemical analyzer Mode1660C manufactured by ALS as themeasurement device.

Example 2 Synthesis of Example Compound A5

In Example 1(1), except that the compound D5 shown below was usedinstead of the compound D1, the example compound A5 was obtained by amethod similar to that of Example 1.

The identification result of the compound thus obtained is shown below.

[MALDI-TOF-MS]

Measured value: m/z=602.88, calculated value: C₃₈H₅₄N₂S₂=602.98 [CVmeasurement]

First Oxidation Potential: −1.05 V Example 3 Synthesis of ExampleCompound A6

In Example 1(1), except that the compound D6 shown below was usedinstead of the compound D1, the example compound A6 was obtained by amethod similar to that of Example 1.

The identification result of the compound thus obtained is shown below.

[MALDI-TOF-MS]

Measured value: m/z=450.58, calculated value: C₂₂H₁₈F₄N₄S₂=450.52 [CVmeasurement]

First Oxidation Potential: −0.95 V Example 4 Synthesis of ExampleCompound A15

In Example 1(1), except that the compound D7 shown below was usedinstead of the compound D1, the example compound A15 was obtained by amethod similar to that of Example 1.

The identification result of the compound thus obtained is shown below.

[MALDI-TOF-MS]

Measured value: m/z=506.43, calculated value: C₃₂H₅₄N₂S₂=506.72 [CVmeasurement]

First Oxidation Potential: −1.05 V Example 5 Synthesis of ExampleCompound B1

In Example 1(1), except that the compound D8 shown below was usedinstead of the compound D1, the example compound B1 was obtained by amethod similar to that of Example 1.

The identification result of the compound thus obtained is shown below.

[MALDI-TOF-MS]

Measured value: m/z=578.72, calculated value: C₃₈H₃₀N₂S₂=578.79 [CVmeasurement]

First Oxidation Potential: −1.02 V Example 6 Synthesis of ExampleCompound C4

In Example 1(1), except that the compound D9 shown below was usedinstead of the compound D1, and the compound D10 shown below was usedinstead of the compound D2, the example compound C4 was obtained by amethod similar to that of Example 1.

The identification result of the compound thus obtained is shown below.

[MALDI-TOF-MS]

Measured value: m/z=504.22, calculated value: C₃₀H₂₄N₄S₂=504.67 [CVmeasurement]

First Oxidation Potential: −0.90 V Example 7 Synthesis of ExampleCompound A2

(1) Synthesis of Compound D13

The following reagents and solvents were charged into a 100-ml eggplantflask.

D11: 0.97 g (8.00 mmol)D12: 1.41 g (16.0 mmol)Conc. hydrochloric acid: 0.1 ml, dehydrated toluene: 30 ml

Next, while water generated by the reaction was removed by theazeotropy, heating and stirring were performed for 3 hours. After thereaction was completed, the solution was concentrated under areduced-pressure condition, so that a crude product was obtained.Subsequently, this crude product was purified using a silica gel columnchromatography (eluent: heptane/ethyl acetate=50/1 to 10/1), so that1.04 g (yield: 68%) of D13 was obtained.

(2) Synthesis of Compound D14

The following reagents and solvent were charged into a 50-ml eggplantflask.

D13: 1.04 g (5.44 mmol)Acetic formic anhydride: 0.72 g (8.16 mmol)

THF: 5 ml

The reaction solution was stirred at room temperature in a nitrogenatmosphere over one night. After the reaction was completed, thesolution was concentrated under a reduced-pressure condition, so that acrude product was obtained. Subsequently, this crude product waspurified using a silica gel column chromatography (eluent: heptane/ethylacetate=50/1 to 10/1), so that 0.95 g (yield: 80%) of D14 was obtained.

(3) Synthesis of Compound D15

The following reagent and solvent were charged into a 50-ml eggplantflask.

D14: 329 mg (1.50 mmol)

Dichloromethane: 10 ml

Next, the reaction solution was cooled to −40° C. while being stirred ina nitrogen atmosphere. Subsequently, 167 mg (1.65 mmol) oftrimethylamine was slowly dripped. Furthermore, 465 mg (1.65 mmol) oftrifluoromethane sulfonic acid anhydride was added. Next, the reactionsolution was stirred at room temperature for 5 hours. After the reactionwas completed, the solution was concentrated under a reduced-pressurecondition, so that a crude product was obtained. Subsequently, thiscrude product was purified using a silica gel column chromatography(eluent: chloroform/ethanol=250/1 to 100/1), and dispersion washing wasfurther performed using a heptane solvent, so that 242 mg (yield: 46%)of D15 was obtained.

(4) Synthesis of Example Compound A2

The following reagent and solvent were charged into a 50-ml eggplantflask in a nitrogen flow atmosphere.

D15: 242 mg (0.69 mmol)

Dehydrated DMF: 10 ml

After this solution was deaerated using nitrogen, 132 mg (2.76 mmol) ofsodium hydride (oil dispersion at 50% to 60%) was charged thereto, andstirring was then performed at room temperature for 2 minutes.Subsequently, 77 mg (0.69 mmol) of potassium tert-butoxide was added,and stirring was performed at room temperature for 6 hours. After thereaction was completed, while stirring was performed, 30 ml of waterwhich was deaerated using nitrogen was slowly added to precipitate atarget product, and the solvent was then removed using a syringe. Next,after the operation of adding 20 ml of water deaerated using nitrogenand removing the solvent using a syringe was again performed twice, 10ml of hexane deaerated using nitrogen was added, and dispersion washingwas performed by an ultrasonic washing machine. Subsequently, afterfiltration was performed using a membrane filter, and a residue waswashed with hexane deaerated using nitrogen, drying was performed at 50°C. under a reduced-pressure condition, so that 76 mg (yield: 55%) of theexample compound A2 in the form of yellow powder was obtained.

The identification result of the compound thus obtained is shown below.

[MALDI-TOF-MS]

Measured value: m/z=402.22, calculated value: C₂₆H₃₀N₂O₂=402.53 [CVmeasurement]First oxidation potential: −1.06 V

Example 8 Synthesis of Example Compound A16

In Example 7(1), except that the compound D16 shown below was usedinstead of the compound D12, the example compound A16 was obtained by amethod similar to that of Example 7.

The identification result of the compound thus obtained is shown below.

[MALDI-TOF-MS]

Measured value: m/z=474.42, calculated value: C₃₂H₃₀N₂O₂=474.59 [CVmeasurement]First oxidation potential: −1.06 V

Example 9 Synthesis of Example Compound AA9

(1) Synthesis of Compound D19

The following reagents and solvents were charged into a 200-ml eggplantflask.

D17: 2,000 mg (9.74 mmol)D18: 1,318 mg (6.49 mmol)Palladium (0) Acetate: 85 mg (0.38 mmol)t-butylphosphine: 262 mg (1.30 mmol)sodium tert-butoxide: 1,247 mg (13.0 mmol)dehydrated toluene: 50 ml

Next, while being stirred in a nitrogen atmosphere, the reactionsolution was heat-refluxed for 6 hours. After the reaction wascompleted, chloroform and water were added to the reaction solution andthen stirred, and an organic layer was separated by liquid-liquidseparation operation. Subsequently, after being washed using a saturatedsodium chloride aqueous solution, the organic layer was dried withsodium sulfate. Next, the organic layer was concentrated under areduced-pressure condition, so that a crude product was obtained.Subsequently, this crude product was purified using a silica gel columnchromatography (eluent: chloroform/heptane=1/4 to 1/1) and was furtherprocessed by dispersion washing using a heptane solvent, so that 1,721mg (yield: 81%) of D19 was obtained.

(2) Synthesis of Compound D20

The following reagents and solvent were charged into a 200-ml eggplantflask.

D19: 1,500 mg (4.58 mmol)Sodium methyl mercaptan, 15% aqueous solution: 3,200 mg (6.87 mmol)Hexamethylphosphoric triamide: 20 ml

Next, while being stirred in a nitrogen atmosphere, the reactionsolution was heat-refluxed for 6 hours. After the reaction wascompleted, 30 ml of 1 N hydrochloric acid was added to the reactionsolution at room temperature and then stirred. Subsequently, water andethyl acetate were added, and an organic layer was separated byliquid-liquid separation operation. Next, after being washed using asaturated sodium chloride aqueous solution, the organic layer was driedwith sodium sulfate. The organic layer was then concentrated under areduced-pressure condition, so that 1,140 mg (yield: 79%) of D20 wasobtained.

(3) Synthesis of Compound D21

The following reagents and solvent were charged into a 100-ml eggplantflask.

D20: 1,000 mg (3.19 mmol)Zinc powder: 333 mg (5.10 mmol)Formic acid: 10 ml

Next, while being stirred in a nitrogen atmosphere, the reactionsolution was heat-refluxed for 6 hours. After the reaction wascompleted, the temperature was decreased to room temperature, andfiltration was performed using a membrane filter, so that a residue wasremoved. Subsequently, 0.60 ml of hydrofluoroboric acid (42% aqueoussolution) was added to the filtrate and was then stirred. Next, 20 ml ofwater was added, and a residue was filtrated, so that a crude productwas obtained. To the crude product thus obtained, diethyl ether wasadded, and dispersion washing was performed using an ultrasonic washingmachine, so that 852 mg (yield: 65%) of D21 was obtained.

(4) Synthesis of Example Compound AA9

The following reagent and solvent were charged into a 50-ml eggplantflask in a nitrogen flow atmosphere.

D21: 500 mg (1.21 mmol)

Dehydrated DMF: 15 ml

After this solution was deaerated using nitrogen, 116 mg (2.42 mmol) ofsodium hydride (oil dispersion at 50% to 60%) was charged thereto, andstirring was then performed for 2 minutes. Subsequently, 135 mg (1.21mmol) of potassium tert-butoxide was added, and stirring was performedat room temperature for 6 hours. After the reaction was completed, whilestirring was performed, 30 ml of water which was deaerated usingnitrogen was slowly added to precipitate a target product, and thesolvent was then removed using a syringe. Next, after the operation ofadding 20 ml of water deaerated using nitrogen and removing the solventusing a syringe was again performed twice, 10 ml of hexane deaeratedusing nitrogen was added, and dispersion washing was performed by anultrasonic washing machine. Subsequently, after filtration was performedusing a membrane filter, and a residue was washed with hexane deaeratedusing nitrogen, drying was performed at 50° C. under a reduced-pressurecondition, so that 250 mg (yield: 65%) of the example compound AA9 inthe form of red powder was obtained.

The identification result of the compound thus obtained is shown below.

[MALDI-TOF-MS]

Measured value: m/z=646.72, calculated value: C₄₅H₅₀N₄=646.99 [CVmeasurement]First oxidation potential: −1.01 V

Example 10 Synthesis of Example Compound AA15

In Example 9(1), except that the compound D22 shown below was usedinstead of the compound D17, the example compound AA15 was obtained by amethod similar to that of Example 9.

The identification result of the compound thus obtained is shown below.

[MALDI-TOF-MS]

Measured value: m/z=747.42, calculated value: C₅₀H₅₄N₂S₂=747.11 [CVmeasurement]First oxidation potential: −1.00 V

Example 11 Synthesis of Example Compound AA2

(1) Synthesis of Compound D25

The following reagents and solvent were charged into a 200-ml eggplantflask.

D23: 1,380 mg (6.49 mmol)D24: 1,200 mg (9.74 mmol)Palladium (0) Acetate: 85 mg (0.38 mmol)t-butylphosphine: 262 mg (1.30 mmol)sodium tert-butoxide: 1,247 mg (13.0 mmol)dehydrated toluene: 50 ml

Next, while being stirred in a nitrogen atmosphere, the reactionsolution was heat-refluxed for 6 hours. After the reaction wascompleted, chloroform and water were added to the reaction solution andthen stirred, and an organic layer was separated by liquid-liquidseparation operation. Subsequently, after being washed using a saturatedsodium chloride aqueous solution, the organic layer was dried withsodium sulfate. Next, the organic layer was concentrated under areduced-pressure condition, so that a crude product was obtained.Subsequently, this crude product was purified using a silica gel columnchromatography (eluent: chloroform/heptane=1/4 to 1/1) and was furtherprocessed by dispersion washing using a heptane solvent, so that 1,408mg (yield: 85%) of D25 was obtained.

(2) Synthesis of Compound D26

The following reagents were charged into a 200-ml eggplant flask.

D25: 1,400 mg (5.49 mmol)Pyridine hydrochloride: 6,344 mg (54.9 mmol)

Next, while being stirred, the reaction solution was heated at 200° C.in a nitrogen atmosphere for 6 hours. After the reaction was completed,ethyl acetate and 0.5 N hydrochloric acid were added to the reactionsolution, and an organic layer was separated by liquid-liquid separationoperation. Subsequently, after being washed using a saturated sodiumchloride aqueous solution, the organic layer was dried with sodiumsulfate. Next, the organic layer was concentrated under areduced-pressure condition, so that a crude product was obtained.Subsequently, this crude product was purified using a silica gel columnchromatography (eluent: chloroform/heptane=1/1 to 5/1) and was furtherprocessed by dispersion washing using a heptane solvent, so that 820 mg(yield: 62%) of D26 was obtained.

(3) Synthesis of Compound D27

The following reagents and solvent were charged into a 100-ml eggplantflask.

D26: 820 mg (3.40 mmol)Trimethyl orthoformate: 10 mlHydrofluoroboric acid (42% aqueous solution): 0.7 ml

Next, the reaction solution was stirred at room temperature in anitrogen atmosphere for 24 hours. After the reaction was completed, aresidue was filtrated using a membrane filter at room temperature, sothat a crude product was obtained. To the crude product thus obtained,diethyl ether was added, and dispersion washing was performed using anultrasonic washing machine, so that 725 mg (yield: 63%) of D27 wasobtained.

(4) Synthesis of Example Compound AA2

The following reagent and solvent were charged into a 50-ml eggplantflask in a nitrogen flow atmosphere.

D27: 500 mg (1.47 mmol)

Dehydrated DMF: 15 ml

After this solution was deaerated using nitrogen, 140 mg (2.94 mmol) ofsodium hydride (oil dispersion at 50% to 60%) was charged thereto, andstirring was then performed at room temperature for 2 minutes.Subsequently, 164 mg (1.47 mmol) of potassium tert-butoxide was added,and stirring was performed at room temperature for 6 hours. After thereaction was completed, while stirring was performed, 30 ml of waterwhich was deaerated using nitrogen was slowly added to precipitate atarget product, and the solvent was then removed using a syringe. Next,after the operation of adding 20 ml of water deaerated using nitrogenand removing the solvent using a syringe was again performed twice, 10ml of hexane deaerated using nitrogen was added, and dispersion washingwas performed by an ultrasonic washing machine. Subsequently, afterfiltration was performed using a membrane filter, and a residue waswashed with hexane deaerated using nitrogen, drying was performed at 50°C. under a reduced-pressure condition, so that 221 mg (yield: 60%) ofthe example compound AA2 in the form of yellowish brown powder wasobtained.

The identification result of the compound thus obtained is shown below.

[MALDI-TOF-MS]

Measured value: m/z=502.98, calculated value: C₃₄H₃₄N₂O₂=502.65 [CVmeasurement]First oxidation potential: −1.01 V

Example 12 Synthesis of Example Compound CC7

In Example 11(1), except that the compound D28 shown below was usedinstead of the compound D23, the example compound CC7 was obtained by amethod similar to that of Example 11.

The identification result of the compound thus obtained is shown below

[MALDI-TOF-MS]

Measured value: m/z=448.32, calculated value: C₂₈H₂₄N₄O₂=448.52 [CVmeasurement]First oxidation potential: −0.91 V

Comparative Example 1 Synthesis of Comparative Compound 3 (1) Synthesisof Compound D31

The following reagents and solvent were charged into a 50-ml eggplantflask

D29: 500 mg (5.88 mmol) (obtained from Tokyo Chemical Industry Co.,Ltd.)D30: 1,923 mg (17.6 mmol)Dehydrated acetonitrile: 15 ml

Next, while being stirred in a nitrogen atmosphere, the reactionsolution was heat-refluxed for 24 hours. After the reaction wascompleted, the reaction solution was cooled, and a precipitated whitesold was filtrated. After the residue was washed with diethyl ether,drying was performed at 100° C. under a reduced-pressure condition, sothat 1,000 mg (yield: 88%) of D31 was obtained.

(2) Synthesis of Comparative Compound 3

In Example 1(3), except that the compound D31 described above was usedinstead of the compound D4, the comparative compound 3 was synthesizedby a method similar to that of Example 1. It was confirmed that thiscompound partially deliquesced during the synthesis and purificationoperations. In addition, the comparative compound 3 is described inNon-Patent Literature 1 and has the structure in which the methyl groupof the compound 1-A in this specification is substituted by a hydrogenatom.

Comparative Example 2 Synthesis of Comparative Compound 4

In Example 1(3), except that the compound D32 (obtained from TokyoChemical Industry Co., Ltd.) shown below was used instead of thecompound D4, the comparative compound 4 was synthesized by a methodsimilar to that of Example 1. It was confirmed that this compoundpartially deliquesced during the synthesis and purification operations.In addition, the comparative compound 4 is described in Non-PatentLiterature 1 and has the same structure as that of the compound 1-B ofthis specification.

Comparative Example 3 Synthesis of Comparative Compound 5

In Example 1(3), except that the compound D33 (obtained from TokyoChemical Industry Co., Ltd.) shown below was used instead of thecompound D4, the comparative compound 5 was synthesized by a methodsimilar to that of Example 1. It was confirmed that this compoundpartially deliquesced during the synthesis and purification operations.In addition, the comparative compound 4 is described in Non-PatentLiterature 2 and has the same structure as that of the compound 1-C ofthis specification.

Examples 13 to 20

In the following examples, an organic light emitting element was formedin which on a substrate, an anode, a hole transport layer, an electronblocking layer, a light emitting layer, an electron transport layer, anda cathode were sequentially formed.

First, an ITO film was formed on a glass substrate, and desiredpatterning was then performed, so that an ITO electrode (anode) wasformed. In this case, the film thickness of the ITO electrode was set to100 nm. The substrate on which the ITO electrode was formed as describedabove was used as an ITO substrate in the following steps.

On the ITO substrate described above, the organic compound layers andthe electrode layer shown in the following Table 2 were continuouslyformed. In addition, the electrode area of the counter electrode (metalelectrode layer, cathode) was set to 3 mm².

TABLE 2 FILM THICKNESS MATERIAL (nm) HOLE TRANSPORT LAYER G-1 30ELECTRON BLOCKING LAYER G-2 10 LIGHT EMITTING LAYER G-3 (HOST) 30 G-4(GUEST) (G-3:G-4 = 98:2 (WEIGHT RATIO)) ELECTRON TRANSPORT G-5 25 LAYERELECTRON INJECTION LAYER G-6 15 G-7 (G-6:G-7 = 50:50 (WEIGHT RATIO))METAL ELECTRODE LAYER Al 100

In this case, before the metal electrode layer was formed, the substratewas left in the air for 10 minutes, and subsequently, the metalelectrode layer was formed. G1 to G6 represent the organic compoundsshown in the following Table 3, and the organic compounds according tothe present disclosure and the comparative compounds 3, 4, and 5 wereeach used for G7, so that the evaluation was performed.

TABLE 3 LIGHT EMISSION G1 G2 G3 G4 G5 G6 G7 CONDITION EXAMPLE 13 HT1 HT7EM13 RD1 ET10 EI6 A6 ∘ EXAMPLE 14 HT1 HT7 EM13 RD1 ET10 EI6 A15 ∘EXAMPLE 15 HT1 HT7 EM13 RD1 ET10 EI6 A16 ∘ EXAMPLE 16 HT1 HT7 EM13 RD1ET10 EI6 B1 ∘ EXAMPLE 17 HT1 HT7 EM13 RD1 ET10 EI6 C4 ∘ EXAMPLE 18 HT1HT7 EM13 RD1 ET10 EI6 AA9 ∘ EXAMPLE 19 HT1 HT7 EM13 RD1 ET10 EI6 AA2 ∘EXAMPLE 20 HT1 HT7 EM13 RD1 ET10 EI6 CC7 ∘ COMPARATIVE HT1 HT7 EM13 RD1ET10 EI6 COMPARATIVE x EXAMPLE 4 COMPOUND 3 COMPARATIVE HT1 HT7 EM13 RD1ET10 EI6 COMPARATIVE x EXAMPLE 5 COMPOUND 4 COMPARATIVE HT1 HT7 EM13 RD1ET10 EI6 COMPARATIVE x EXAMPLE 6 COMPOUND 5

As a result, when light emission was confirmed by applying a voltage of8 V, although the light emission of the organic compound according tothe present disclosure was confirmed, the light emission of each of thecomparative compounds 3, 4, and 5 was not confirmed. The reason for thisis believed that when exposed to the air, the comparative compounds 3,4, and 5 were denatured, and hence, the electron injection propertythereof was lost.

Examples 21 to 29

By the use of the organic compound layers and the electrode layer shownin the following Table 4, elements were formed in a manner similar tothat of Examples 13 to 20.

TABLE 4 FILM THICKNESS MATERIAL (nm) HOLE TRANSPORT LAYER G-1 30ELECTRON BLOCKING LAYER G-2 10 LIGHT EMITTING LAYER G-3 (HOST) 30 G-4(GUEST) (G-3:G-4 = 98:2 (WEIGHT RATIO)) ELECTRON TRANSPORT G-5 25 LAYERELECTRON INJECTION LAYER G-6 15 G-7 (G-6:G-7 = 50:50 (WEIGHT RATIO))METAL ELECTRODE LAYER G-8 100

In this case, after the organic compounds and the metals shown in thefollowing Table 5 were used for G1 to G6 and G8, and the organiccompound according to the present disclosure was used for G7, theevaluation was performed. In addition, when the metals were mixedtogether, the mixing ratio thereof was represented by the weight ratioshown in the table. By applying the voltage between the ITO electrodefunctioning as the anode and the counter electrode functioning as thecathode of the organic light emitting element thus obtained so as toobtain a current density of 100 mA/cm², the light emission efficiencyand the application voltage were measured. The results are shown inTable 5.

As for the measurement devices, the current-voltage characteristics weremeasured using a micro-ammeter 4140B manufactured by Hewlett-Packard,and the light emission luminance was measured using BM7 manufactured byTopcon Corp.

TABLE 5 LIGHT EMISSION EFFICIENCY VOLTAGE G1 G2 G3 G4 G5 G6 G7 G8 (cd/A)(V) EXAMPLE 21 HT6 HT7 EM13 RD1 ET10 EI6 A1 Ag 4 8 EXAMPLE 22 HT2 HT7EM3 BD4 ET10 EI6 A6 Ag 6 8 EXAMPLE 23 HT6 HT7 EM4 GD4 ET9 EI6 B1 Au 17 7EXAMPLE 24 HT6 HT8 EM8 RD4 ET9 EI6 C1 Ag:Mg = 1:1 7 7 EXAMPLE 25 HT2 HT8EM14 RD2 ET10 EI6 C5 Ag 4 7 EXAMPLE 26 HT2 HT7 EM4 BD1 ET9 EI6 A2 Ag:Cu= 5:1 5 8 EXAMPLE 27 HT6 HT7 EM13 RD1 ET10 EI6 AA9 Ag 4 8 EXAMPLE 28 HT2HT7 EM3 BD4 ET10 EI6 AA12 Ag 6 8 EXAMPLE 29 HT2 HT8 EM14 RD2 ET10 EI6AA15 Ag 4 7

Examples 30 to 37

In the following examples, an organic light emitting element was formedin which an anode, a hole transport layer, an electron blocking layer, alight emitting layer, a hole blocking layer, an electron transportlayer, and a cathode were sequentially formed on a substrate. By the useof the organic compound layers and the electrode layer shown in thefollowing Table 6, element formation and measurement were performed in amanner similar to that of Examples 13 to 20.

TABLE 6 FILM THICKNESS MATERIAL (nm) HOLE TRANSPORT LAYER G-1 30ELECTRON BLOCKING LAYER G-2 10 LIGHT EMITTING LAYER G-3 (HOST) 30 G-4(GUEST) (G-3:G-4 = 98:2 (WEIGHT RATIO)) HOLE BLOCKING LAYER G-5 10ELECTRON TRANSPORT G-6 26 LAYER ELECTRON INJECTION LAYER G-7 4 METALELECTRODE LAYER G-8 100

In this case, after the organic compounds and the metals shown in thefollowing Table 7 were used for G1 to G6 and G8, and the organiccompound according to the present disclosure was used for G7, evaluationwas performed. In addition, when the metals were mixed together, themixing ratio thereof was represented by the weight ratio shown in thetable.

TABLE 7 LIGHT EMISSION EFFICIENCY VOLTAGE G1 G2 G3 G4 G5 G6 G7 G8 (cd/A)(V) EXAMPLE 30 HT6 HT7 EM13 RD1 ET10 EI6 A15 Ag:Mg = 1:1 4 8 EXAMPLE 31HT6 HT7 EM4 BD6 ET10 EI9 A16 Ag 5 9 EXAMPLE 32 HT2 HT7 EM7 GD6 ET9 EI17A2 Au 20 8 EXAMPLE 33 HT1 HT8 EM14 RD1 ET9 EI14 A14 Ag:Al = 1:1 5 8EXAMPLE 34 HT2 HT8 EM8 BD8 ET10 EI12 C4 Al 4 9 EXAMPLE 35 HT6 HT7 EM4BD6 ET10 EI9 AA17 Ag 5 9 EXAMPLE 36 HT2 HT8 EM8 BD8 ET10 EI12 AA12 Al 49 EXAMPLE 37 HT1 HT8 EM14 RD1 ET9 EI14 AA18 Ag:Al = 1:1 5 8

As described above with reference to the examples, when the fulvalenecompound according to this embodiment is used for the electron injectionlayer, an organic light emitting element stable in the air can beformed. Accordingly, a stable element having a long serviceable life canbe obtained.

As has thus been described, the fulvalene compound according to thepresent disclosure is a compound having a high stability in the air. Inaddition, an organic light emitting element in which the fulvalenecompound according to the present disclosure is used for the electroninjection layer is stable against moisture and oxygen. Accordingly, anorganic light emitting element having a high light emission efficiencyand excellent life characteristics can be provided.

The present disclosure can provide a highly stable organic lightemitting element containing a fulvalene compound which can be stablypresent due to its low reactivity with oxygen and moisture in the air.

While the present disclosure has been described with reference toexemplary embodiments, it is to be understood that the disclosure is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2015-138156, filed Jul. 9, 2015, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. An organic electronic element comprising: a pairof electrodes; and an organic compound layer disposed between the pairof electrodes, wherein the organic compound layer contains an organiccompound represented by the following general formula [1]

in the formula [1], Ar₁ and Ar₂ are each independently selected from anaromatic hydrocarbon group having 6 to 24 carbon atoms or aheteroaromatic ring group having 3 to 23 carbon atoms, Ar₁ and Ar₂ eachmay have a substituent selected from the group consisting of a halogenatom, a cyano group, an alkyl group having 1 to 4 carbon atoms, a phenylgroup, a tolyl group, a xylyl group, a mesityl group, and a cumenylgroup, R₁ to R₄ are each independently selected from the groupconsisting of a hydrogen atom, a halogen atom, a cyano group, an alkylgroup having 1 to 8 carbon atoms, a phenyl group with or without asubstituent, and a pyridyl group with or without a substituent, R₁ andR₂ and R₃ and R₄ each may form a benzene ring, the benzene ring may haveas a substituent, at least one of a halogen atom, a cyano group, analkyl group having 1 to 8 carbon atoms, a phenyl group with or without asubstituent, and a pyridyl group with or without a substituent, and X₁and X₂ represent a sulfur atom or an oxygen atom, and X₁ and X₂represent the same atom.
 2. An organic light emitting elementcomprising: an anode; a cathode; and a light emitting layer disposedbetween the anode and the cathode, wherein the organic light emittingelement has an organic compound layer between the cathode and the lightemitting layer, and the organic compound layer contains an organiccompound represented by the following general formula [1]

in the formula [1], Ar₁ and Ar₂ are each independently selected from anaromatic hydrocarbon group having 6 to 24 carbon atoms or aheteroaromatic ring group having 3 to 23 carbon atoms, Ar₁ and Ar₂ eachmay have a substituent selected from the group consisting of a halogenatom, a cyano group, an alkyl group having 1 to 4 carbon atoms, a phenylgroup, a tolyl group, a xylyl group, a mesityl group, and a cumenylgroup, R₁ to R₄ are each independently selected from the groupconsisting of a hydrogen atom, a halogen atom, a cyano group, an alkylgroup having 1 to 8 carbon atoms, a phenyl group with or without asubstituent, and a pyridyl group with or without a substituent, R₁ andR₂ and R₃ and R₄ each may form a benzene ring, the benzene ring may haveas a substituent, at least one of a halogen atom, a cyano group, analkyl group having 1 to 8 carbon atoms, a phenyl group with or without asubstituent, and a pyridyl group with or without a substituent, and X₁and X₂ represent a sulfur atom or an oxygen atom, and X₁ and X₂represent the same atom.
 3. The organic light emitting element accordingto claim 2, wherein the Ar₁ and Ar₂ each have at least one fluorine atomas a substituent.
 4. The organic light emitting element according toclaim 2, wherein the Ar₁ and Ar₂ each have at least one tert-butyl groupas a substituent.
 5. The organic light emitting element according toclaim 2, wherein the organic compound layer further contains a compounddifferent from the organic compound represented by the general formula[1].
 6. The organic light emitting element according to claim 5, whereinthe weight rate of the compound different from the organic compoundrepresented by the general formula [1] is more than 0 to 80 percent byweight when the total of the organic compound represented by the generalformula [1] and the compound different therefrom is assumed to be 100percent by weight.
 7. The organic light emitting element according toclaim 2, wherein the organic compound layer is in contact with thecathode.
 8. The organic light emitting element according to claim 2,wherein the organic light emitting element has a plurality of lightemitting layers including the above light emitting layer, at least oneof the plurality of light emitting layers is a light emitting layeremitting color light different from that of the rest of the plurality oflight emitting layers, and the organic light emitting element emitswhite light.
 9. A display device comprising: a plurality of pixels,wherein the pixels each have the organic light emitting elementaccording to claim 2 and an active element connected thereto.
 10. Thedisplay device according to claim 9, wherein the active element is atransistor, and the transistor has an oxide semiconductor in an activeregion.
 11. A lighting device comprising: the organic light emittingelement according to claim 2; and a switching element connected thereto.12. A lighting device comprising: a substrate; a heat dissipationportion; and the organic light emitting element according to claim 2,wherein the heat dissipation portion is a heat dissipation portiondissipating heat in the device to the outside thereof.
 13. An imageforming device comprising: a photoreceptor; an exposure portion exposingthe photoreceptor: a charging portion charging the photoreceptor; and adeveloping portion imparting a developer to the photoreceptor, whereinthe exposure portion has the organic light emitting element according toclaim
 2. 14. An exposure device which exposes a photoreceptor, theexposure device comprising a plurality of the organic light emittingelements according to claim 2, wherein the organic light emittingelements are arranged along a long axis direction of the photoreceptorto form at least one column.
 15. An organic photoelectric conversionelement comprising: an anode; a cathode; and an organic photoelectricconversion layer disposed between the anode and the cathode, wherein theorganic photoelectric conversion element further comprises an organiccompound layer between the cathode and the organic photoelectricconversion layer, and the organic compound layer contains an organiccompound represented by the following general formula [1]

in the formula [1], Ar₁ and Ar₂ are each independently selected from anaromatic hydrocarbon group having 6 to 24 carbon atoms or aheteroaromatic ring group having 3 to 23 carbon atoms, Ar₁ and Ar₂ eachmay have a substituent selected from the group consisting of a halogenatom, a cyano group, an alkyl group having 1 to 4 carbon atoms, a phenylgroup, a tolyl group, a xylyl group, a mesityl group, and a cumenylgroup, R₁ to R₄ are each independently selected from the groupconsisting of a hydrogen atom, a halogen atom, a cyano group, an alkylgroup having 1 to 8 carbon atoms, a phenyl group with or without asubstituent, and a pyridyl group with or without a substituent, R₁ andR₂ and R₃ and R₄ each may form a benzene ring, the benzene ring may haveas a substituent, at least one of a halogen atom, a cyano group, analkyl group having 1 to 8 carbon atoms, a phenyl group with or without asubstituent, and a pyridyl group with or without a substituent, and X₁and X₂ represent a sulfur atom or an oxygen atom, and X₁ and X₂represent the same atom.
 16. An image taking element comprising: aplurality of pixels; and a signal processing circuit connected to theplurality of pixels, wherein at least one pixel has the organicphotoelectric conversion element according to claim 15 and a readingcircuit connected thereto.
 17. The image taking element according toclaim 16, wherein the pixel further has a different type of organicphotoelectric conversion element, and the different type of organicphotoelectric conversion element is an organic photoelectric conversionelement performing photoelectric conversion of color light differentfrom that of the organic photoelectric conversion element, and theorganic photoelectric conversion element and the different type oforganic photoelectric conversion element are laminated to each other.18. An image taking device comprising: an image taking optical system;and an image taking element receiving light which passes through theimage taking optical system, wherein the image taking element is theimage taking element according to claim
 16. 19. The image taking deviceaccording to claim 18, further comprising a receiving portion receivinga signal from the outside, wherein the signal is a signal controlling atleast one of an image taking region of the image taking device, thestart of image taking, and the stop of image taking.
 20. The imagetaking device according to claim 19, further comprising a transmittingportion transmitting an obtained image to the outside.